Chiral stationary phases for enantiomers separation and their preparation

ABSTRACT

The present invention describes new chiral stationary phases and optically active compounds therein contained. The optically active compounds contained in the stationary phases are represented by the formula of structure (I), containing at least one asymmetric carbon atom, and a substituent acting as a spacer. The stationary phases of the present invention are useful in the preparation of chromatographic columns useful for the separation of enantiomers.

This appln is a 371 of PCT/EP99/02869 filed on Jun. 28, 1999.

STATE OF THE ART

The separation of enantiomers by means of liquid chromatography (LC)using chiral stationary phases is based on the reversible diasteromericassociation between the chiral environment in the column and theenantiomers in the solution (S. Allenmark, “ChromatographicEnantioseparation”, 2nd Edition, Ellis Horwood, N.Y., 1991, pp.1007-1008).

The chiral stationary phases for LC are normally classified on the basisof their general structures. One group is based on either synthetic ornatural polymers and is totally or intrinsically chiral.

Another group is made up of chiral selectors with a low molecular weightbound to a solid, incompressible, matrix, generally silica. The latterprovides remarkable advantages with respect to the former since thechiral selectors can be designed rationally (K. B. Lipkowitz, ModellingEnantiodifferentiation in Chiral Chromatography, in “A PracticalApproach to Chiral Separation by Liquid Chromatography”, G. SubramanianEditor, VCH, Weinheim, 1994, pp. 19-55).

This implies that they can be selected on a rational basis; in fact,their enantioselective features can often be evaluated by means of NMRstudies or can be singled out thanks to computer modelling according tothe various types of chemical interactions.

Among the most frequently used chiral selectors bound to a solid supportit is worth quoting the “crown ethers” (E. P. Kyba et al., J. Am. Chem.Soc., 1978, 100: 4555-4568), the charge-transfer complexes (W. H. Pirkleet al., J. Am. Chem. Soc. 1986, 108: 352) the chiral selectors based onhydrogen bonds (see e.g. S. Hara et al., J. Chromatogr., 1979, 186: 543)and other types of chiral selectors (P. Salvadori et al., Tetrahedron,1987, 43, 4969).

All these products exhibit some limitations with respect to theirenantioseparating ability, which are due either to the high number offunctional groups or structural subunits that participate in theinteraction with the enantiomers in solution.

The range of application of chiral selectors should therefore be widenedup so as to promote the use and versatility of chromatography based onstationary chiral phases.

Is a fungicide widely used in agriculture; some of its derivatives suchas glutathione are described in Tetrahedron, 1995, 51: 2331. None ofthese derivatives is used in chromatography.

FIELD OF THE INVENTION

This invention relates to new derivatives of1,3-dicyano-2,4,5,6,-tetrachlorobenzene containing one or more chiralgroups and one group acting as a spacer. The stationary phases obtainedfrom these derivatives provide an efficient separation of enantiomers.

SUMMARY

The present invention describes new chiral stationary phases, and theoptically active compounds therein contained. The optically activecompounds contained in the stationary phases are represented by theformula of structure (I), which comprise at least one asymmetric carbonatom and a substituent acting as a spacer. The stationary phases of thepresent invention can be used in the preparation of chromatographiccolumns useful for the analytical and preparative separation ofenantiomers.

BRIEF DESCRIPTION OF THE FIGS.

FIG. 1: preparation of the FSC 1 chiral stationary phase

FIG. 2: preparation of the FSC 5 chiral stationary phase

FIG. 3: preparation of the FSC 10 chiral stationary phase

FIG. 4: preparation of the FSC 20 chiral stationary phase

FIG. 5a-p: Z, X and Y substituents of the chiral stationary phases(1)-(28) as prepared in the experimental part. The reference structureis that of formula (I).

FIG. 6: list of racemic mixtures

DETAILED DESCRIPTION OF THE INVENTION

The present invention regards chiral stationary phases forchromatography based on new chiral derivatives, hereinafter referred toas “chiral selectors”.

The chiral selectors, that form the first object of the presentinvention are represented by the general formula (I):

where:

X=NR₁—CHR₂R₃

R₁ represents H, alkyl C₁-C₆ linear or branched,

R₂ represents H, alkyl C₁-C₆ linear or branched, aryl or arylalkylpossibly containing an heteroatom, being said aryl or arylalkyloptionally substituted with—OH, —CH₂CONH₂,

R₃ represents:

alkyl C₁-C₆ linear or branched, (CH₂)_(p)—COOH, (CH₂)_(p)—CONH₂,(CH₂)_(p)—CONHR₄, (CH₂)_(p)—NHCOR₄, (CH₂)_(p)—CON(R₄R₅), CONHCH(R₄)CONHR₄, (CH₂)_(p)—NHCOCH(R₄)NHCOR₄, C₆H₄—CH₂—NHCOCH(R₄)NHCOR₄,CH₂NH(CH₂)_(p)—NHCOCH(R₄)NHCOR₄

where p is an integer from 0 to 4, R₄ and R₅ independently of each otherrepresent (a) alkyl C₁-C₆ linear or cyclic, (b) aryl, (c) a spacer groupof formula (CH₂)n-Si— (OR₆)₃ where n is comprised between 1 and 10 andR₆ represents an alkyl C₁-C₄; said groups (a) and (b) are optionallysubstituted with alkyl C₁-C₄, aryl, cycloalkyl C₅-C₆, NO₂, OCH₃, or:

(i) R₁ forms together with R₂, with the carbon atom bound to R₂ and withthe nitrogen, a 5-6 membered ring, or

(ii) R₂ forms with R₃ and with the carbon atom bound to R₂ and R₃ a 5-6membered ring substituted by —NHCOR₄, or by —NHCOCH(R₄)NHCOR₄, R₄ beingas above defined;

Y e Z independently of each other represent: chloro, X group where X hasthe meanings given above, a spacer group of formula —A(CH₂)n-Si—(OR₆)₃where A represents NH or O, preferably NH, and n and R₆ have themeanings given above; with the proviso that said formula (I) contains:(a) one to three X groups containing at least one chiral atom, and (b)only one spacer group as above defined.

Generally, in formula (I), the X group represents preferably anα-aminoacid, ester of aminoacid, amide of aminoacid, arylalkylalcohol,arylcarboxylic acid, arylcarboxylic acid ester, arylcarboxylic acidester, aminoamide, arylalkylamine. The arylalkyl groups quoted above arepreferably represented by the benzyl group.

The aryl groups are preferably represented by either phenyl or naphthyl.The derivatives of formula (I) always contain at least one chiral carbonatom. This carbon atom is always contained in the X group and isnormally represented by the carbon C* of the C*HR₂R₃ group or it iscontained in the R₃ substituent. Within the formula (I) herein defined,it is possible to identify subgroups of products particularly useful forthe purpose of this invention.

A first group of selectors preferred is represented by formula (I)where:

R₁ represents H, alkyl C₁-C₆ linear or branched, R₂ represents H, alkylC₁-C₆ linear or branched, aryl, arylalkyl, CH₂CONH₂, or R₁ forms withR₂, with the carbon atom bound to R₂ and with N a 5-6 membered ring; R₃represents alkyl C₁-C6 linear or branched, (CH₂)_(p)—CONHR₄,(CH₂)_(p)—CON(R₄R₅), where p, R₄ and R₅ have the meanings given above.

A second group of selectors preferred is represented by formula (I)where:

R₁ represents H, R₂ represents: H, R₃ represents (CH₂)_(p)—NHCOR₄,CH₂—NHCOR₄, where p, R₄ have the meanings given above; or R₂ forms withR₃ and the carbon atom bound to R₂ and R₃ a 5-6 membered ring.

A third group of preferred selectors is represented by formula (I)where:

R₁ represents H, R₂ represents H, or R₂ forms with R₁, with the carbonatom bound to R₂ and with N a 5-6 membered ring; R₃ representsCONHCH(R₄)CONHR₄, where p, R₄ have the meanings given above.

A fourth group of selectors preferred is represented by formula (I)where:

R₁ represents H, R₂ represents H, , R₃ represents:,(CH₂)_(p)—NHCOCH(R₄)NHCOR₄, C₆H₄—CH₂—NHCOCH(R₄)NHCOR₄,CH₂NH(CH₂)_(p)—NHCOCH(R₄)NHCOR₄; or R2 forms with R3 and with the carbonatom bound to R2 and R3 a 5-6 membered ring substituted withNHCOCH(R₄)NHCOR₄ ; p and R₄ having the meanings given above.

Preferred selectors of formula (I) are quoted in the following list. Thenames in bracket refer to the corresponding chiral stationary phaseswhose structure are reported in FIG. 5:

5-Chloro-4,6-di-[R-1-(naphth-1-yl)ethyl]amino-2-(3-trimethylsilylpropyl)amino-1,3-dicyanobenzene(FSC 1)

4-[(3,5-dimethylanilido)-L-phenylalaninyl]-6-(3-triethoxysilyl)propylamino-2,5-dicloro-1,3-dicyanobenzene,and4-[(3,5-Dimethyanilido)-L-phenylalaninyl]-2-(3-triethoxysilyl)propylamino-5,6-dicloro,1,3-dicyanobenzene (FSC 3)

4-[(naphth-1-yl)amido)-L-phenylalaninyl]-2-(3-triethoxypropyl)amino-5,6-dichloro-1,3-dicyanobenzeneand4-[(Naphth-1-yl)amido)-L-phenylalaninyl]-6-(3-triethoxypropyl)amino-2,5-dichloro-1,3-dicyanobenzene(FSC 4)

4-[R-1-(naphth-1-yl)ethyl]amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzeneand4-[R-1-(naphth-1-yl)ethyl]amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzene(FSC 6)

4-{n-butyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzene,and4-{n-butyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-2-(3-trimethylsilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene (FSC 7)

4-{n-butyl-[R-1-(cyclohexyl)ethyl-N-R-(naphth-1-yl)methyl]acetamido}amino-6-(3-triethoxysilylpropyl)amino-2,5-trichloro-1,3-dicyanobenzeneand4-{n-butyl-[R-1-(cyclohexyl)ethyl-N-R-(naphth-1-yl)methyl]acetamido}amino-2-(3-triethoxysilylpropyl)amino-5,6-trichloro-1,3-dicyanobenzene(FSC 8)

4-{n-butyl-[N-R-1-(cyclohexyl)ethyl-N-3,5-dinitrobenzyl]acetamido}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzeneand4-{n-butyl-[N-R-1-(cyclohexyl)ethyl-N-3,5-dinitrobenzyl]acetamido}amino-2-(3-triethoxysilylpropyl)amino-5,6trichloro-1,3-dicyanobenzene(FSC 9)

4-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]ethyl}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzeneand4-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]ethyl}amino-2-(3-triethoxysilylpropylamino-5,6-dichloro-1,3-dicyanobenzene (FSC 10)

4-{methyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene,and4-{methyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-6-(3-trimethylsilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzene (FSC 11)

4-[3,5-dimethylanilido)-L-alaninyl]-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-[3,5-dimethylanilido)-L-alaninyl]-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene(FSC 14)

4-(cyclohexylamido-L-alaninyl)-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-(cyclohexylamido-L-alaninyl)-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene(FSC 15)

4-[(3,5-dimethylanilido)-prolinyl]-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-[(3,5-dimethylanilido)-prolinyl]-5,6-Dichloro-2-(3-triethoxysilylpropyl)amino1,3-dicyanobenzene(FSC 16)

4-(prolinyl-cyclohexylamide)-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-(prolinyl-cyclohexylamide)-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene(FSC 17)

4-[L-prolinyl-L-alanilyl-(3,5-dimethylanilide)]-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-[L-prolinyl-L-alanilyl-(3,5-dimethylanilide)]-2,5-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene(FSC 18)

4-{[2-(3,5-dinitrobenzoyl)-cyclohexyl]amide}-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and 4-(2-(3,5-dinitrobenzoyl)-cyclohexyl]amide)amino-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene(FSC 22)

4-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]cyclohexyl}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzeneand4-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]cyclohexylamino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene(FSC 23)

Formula (I) entails the presence of at least one X chiral substituentbound in meta position with respect to the Z group. When Y═X, formula(I) can contain two chiral groups in meta position with respect to the Zgroup, by conferring thus specific symmetry characters: if the two Xsubstituents are structurally and stereochemically different from oneanother, the molecule acquires C1 symmetry; on the other side if the twoX substituents are structurally and stereochemically identical, themolecule acquires C2 symmetry. Another possibility of having a chiralselector of formula (I) with two chiral groups on thetetrachloro-dicyanobenzene is allowed when Z═X.

Formula (I) always contains one spacer group as above defined. Preferredspacer groups are those where R₆ represents ethyl and n is 3. A mostpreferred spacer is the (3-triethoxylsilylpropyl)amino group. As evidentfrom formula (I), the spacer group can be indifferently present as an Y,Z group or as a further substituent of the chiral group. In this lattercase (i.e. when the spacer is defined by the substituent R₄ or R₅,option (c)), the R₃ substituents are preferably chosen among:(CH₂)_(p)—CONHR₄, (CH₂)_(p)—CON(R₄R₅), CONHCH(R₄) CONHR₄. By means of acovalent binding that involves the oxygen atoms of the (OR₆)₃ groups,the spacer group allows to bind the molecule of formula (I) to a solidsupport and to form chiral stationary phases for chromatography. Thelinkage that forms can be represented in this way:

The solid support can be of either of organic or, preferably, inorganictype. Suitable examples of solid inorganic support are silica gel,alumina, kaolin, titanium oxide, magnesium, silicate, syntheticpolymers. The preferred solid support is silica (e.g. silica gel).

The present invention relates also to a process for the production ofchiral stationary phases. This process entails the use of1,3-dicyano-2,4,5,6-tetrachlorobenzene as a reagent; as mentioned above,this product is commercially available.

In agreement with the structural requirements of formula (I), thepresent process entails the introduction of only one spacer group, andfrom one to three chiral X groups.

The process is thus characterised by comprising the following separatereaction steps which can take place in any order:

introduction of one or more chiral X groups on the dicyanobenzene ring,

introduction of the spacer group either on dicyanobenzene ring or on achiral group already present on the dicyanobenzene ring,

formation of covalent linkage between the spacer group and a solidsupport.

According to a first specific embodiment, the above described processcomprises the following steps:

a) introduction of one or more chiral X groups on the1,3-dicyano-2,4,5,6-tetrachlorobenzene by substitution of one or bothchlorine atoms in position 4 or 6 with the obtainment of chiralderivatives of formula (II).

 where X and Y have the meanings defined above, with the only differencethat they do not contain any spacer group.

b) introduction of a spacer group in the derivative of formula (II)obtained in step a), wherein said spacer group is introduced either bysubstitution of one chlorine atom on the dicyanobenzene ring or it isintroduced on the X group, with the obtainment of the chiral selector offormula (I).

c) formation of covalent linkage between the spacer group and the solidsupport with the obtainment of the chiral stationary phase.

According to a second specific embodiment, the above described processcomprises the following steps:

a) introduction of one or more chiral X groups on the1,3-dicyano-2,4,5,6-tetrachlorobenzene by substitution of one or bothchlorine atoms in position 4 or 6 of the dicyanobenzene ring with theobtainment of chiral derivatives of formula (II).

b) formation of covalent linkage between a spacer group and a solidsupport.

c) introduction of the spacer group linked to the solid support obtainedin step b) either on position 2 or 4 or 6 of the dicyanobenzene ring oron the X group of chiral selector of formula (II) obtained in a) withthe obtainment of the chiral stationary phase.

According to a third specific embodiment, the above described processcomprises the following steps:

a) introduction of a spacer group on1,3-dicyano-2,4,5,6-tetrachlorobenzene by substitution of one chlorineatom in position 4 or 6 of the dicyanobenzene ring, where said spacergroup is possibly previously bounded to the solid support

b) introduction of one or more chiral X groups on the dicyanobenzenering by substitution of either one or both chlorine atoms in position 2or 4 or 6 of the compound of step a), possibly formation of covalentlinkage between the spacer group and the solid support, with theobtainment of chiral stationary phases.

The chiral X groups are introduced in the1,3-dicyano-2,4,5,6-tetrachlorobenzene by substitution of one or more ofthe chlorine atoms in position 2,4,6, using suitable reagents containingthe X group.

Examples of these reagents are α-aminoacids, α-arylalkyl amine,secondary alcohols, amides or esters of chiral carboxylic acids.Examples of specific reagents are: 1-phenylethylamine, proline,(1-(naphth-1-yl)ethylamine, phenylalanine, phenylglycine, n-butylamine,naphthylethylamine, 3,5-dimethylaniline, cyclohexylethylamine,sarcosine, asparagine.

The spacer group is preferably introduced by reaction with a reagent offormula AH—(CH₂)n-Si—(OR₆)₃ where A═NH₂, OH, and where n and R₆ have themeanings described above.

The introduction of X, Y and Z groups is performed by heating thereagents in a suitable solvent, possibly in the presence of an excess ofthis solvent. The operational temperature ranges from 20° C. to 150° C.and the reaction time ranges from 60 minutes to 80 hours. When a singleX group is introduced in the ring, then the reaction is preferablyperformed in a polar solvent or in a mixture of solvents. Moreover thetimes are shorter, ranging from 1 to 5 hours. In case derivatives withtwo X substituents are to be prepared then it is preferable to use anexcess of liquid reagent (molar excess 50-100 times) and then carry onheating up to 80 hours.

The X chiral groups that are present in the stationary phases that arethe object of this invention are in an optically pure form, that is theyhave a specific stereochemical configuration. The synthesis of theproducts of formula (II) and (I) that are the object of the presentinvention are carried out by using the nucleophylic reagents containingthe X group in an optically pure form.

The covalent binding between the spacer group and the solid support isobtained according to known chemical reactions comprising heating athigh temperature in the presence of an organic solvent.

The preparation of the chiral stationary phases based on chiralselectors of formula (I), and the specific structures of some chiralstationary phases are shown in FIGS. 1-5.

FIG. 1,2,3,4 show the preparation of stationary chiral phases called FSC1, 5, 10, 20. The experimental part reports the preparation ofstationary phases starting from a variety of chiral selectors of formula(I).

The stationary phases (whose structures are illustrated in FIG. 5) thatare the object of the present invention allow the separation of severalracemic mixtures of commercial interest. The use of these chiralstationary phases for the enantiomeric separation by chromatography, andin particular their use in the preparation of high performance liquidchromatographic columns (HPLC) constitutes a further aspect of thepresent invention. Moreover, the present invention comprises a method ofseparation of enantiomeric mixtures by means of such chiral stationaryphases. Examples of isomer separation by means of stationary phasesobject of the invention are reported in the experimental part.

The stationary phases which are object of the present invention allowboth the analytical and preparative separation of enantiomers ofstructurally different compounds and to determine the enantiomericcomposition obtained by means of various asymmetric syntheses (V.Vinkovic et al., Tetrahedron, 1997, 53, 689; E. Ljubovic, et al.Tetrahedron: Asymm., 1997, 8,1).

The separation process takes place by means of several efficientinteractions for the enatioselection and also by means of new kinds ofcumulative interaction that can be performed specifically and only bymeans of the selectors of formula (I) claimed in the present invention.In particular, the high electronegativity of the chlorine atom and thedipolar moment of the CN group of the chiral selector promotes thesetting of polar interactions and the formation of hydrogen bonds withthe enantiomers to be separated.

Moreover, the lack of π electrons on the aromatic ring that is measuredwith the sum of the σ constants of each substituents (chlorine, cyano-amino, amido, alkoxy) is higher than the one calculated for the amidederivative of N-(3,5-dinitrobenzoyl)-aminoacid used by Pirkle as achiral selector (Pirkle, J. Am. Chem. Soc. 1986, 108, 352). The newstationary phases are therefore remarkably more effective in theformation of interactions of the π-π kind with strong π-donor groupspresent in the chiral compounds to be separated. In particular, thestationary phases claimed turned out to be effective in the separationof a wide number of enantiomers such as α-aminoacids and of theirderivatives with N- and O-protection, carboxylic acids and their estersor heterocyclic or acyclic amides, amines, alcohols, thiols, epoxidesand aziridines.

The examples listed hereunder aim at illustrating the invention withouta limitative purpose.

EXAMPLES Examples of Preparation of Chiral Selectors and StationaryPhases Example 15-Chloro-4,6-di-[R-1-(naphth-1-yl)ethyl]amino-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene

The mixture of 2,4,5,6-tetrachloro-1,3-dicyanobenzene (2.0 g; 7.5 mmol)and [R-1-(naphth-1-yl)ethyl]amine (5.13 g; 30.0 mmol) is heated at 100°C. in DMF (30 ml) for 48 hr. Then the solvent is evaporated to dryness,the crude product dissolved in toluene and purified by chromatography onsilica gel column (100 g), using toluene as eluent. It is obtained 3.78g (93%) of slightly yellow crystals of the pure product:2,5-dichloro-4,6-di-[R-1-(naphth-1-yl)ethyl]amino-1,3-dicyanobenzene.The analysis of this product is as follows: Anal. calcd. forC₃₂H₂₄N₄Cl₂: C, 71.77; H, 4.51; and N, 10.4. Found: C, 71.72; H, 4.56;and N, 10.42%.

This compound (3.28 g, 6.13 mmol) in excess of3-aminopropyltriethoxysilane (10.0 ml, 42.5 mmol) is heated at 110° C.for 24 hrs. The solution is cooled to room temperature, diluted withtoluene, applied on to flash chromatography column with silica gel andeluted with toluene. The pure product (3.85 g, 87%) is isolated aspale-yellow oil.

IR (KBr): 3400, 3060, 2980, 2920, 2200, 1590, 1510, 1470, 1450, 1390,1380, 1360, 1300, 1260, 1230, 1200, 1160, 1100, 1080, 1010, 950, 860,800, 780, 720 cm⁻¹.

Anal. calcd. for C₄₁H₄₆N₅SiO₃Cl (720.36); C, 68.35; H, 6.43; N, 9.72;Found; C, 68.31; H, 6.48; N, 9.68%.

Example 2 Chiral Stationary Phase FSC 1

The compound of example 1 (7.70 g; 10.6 mmol) and silica gel LiChrospherSi 100 (4.18 g) are heated under reflux in dry toluene over 72 hr.Chiral stationary phase FSC 1 (5.7 9) is isolated as pale-yellowamorphous material.

Analysis, found; C 17.81, H 2.00, N 2.77%. According to elementalanalysis it is calculated that 0.21 mmol of the chiral selector is boundon 1.0 g of silica gel.

Example 3 4-N-L-Phenylglycinyl-2,5,6-trichloro-1,3-dicyanobenzene

To 2,4,5,6-tetrachloro-1,3-dicyanobenzene (4.0 g, 15.0 mmol) in MeOH(100 ml) is added to a warm solution of L-phenylglycine (4.55 g, 30.0mmol) and sodium carbonate (3.18 g, 30.0 mmol) in water (100 ml). Thereaction mixture is stirred and heated under reflux for 1.5 hr, thencooled and filtered. The filtrate is acidified by addition of 1 M HCl(50 ml), and the precipitated product is separated by filtration. It iswashed with water and dried in vacuo at ambient temperature.Crystallisation from ethanol afforded 1.40 g (25%) of pure product,white powder.

IR (KBr): 3500, 3320, 2220, 1715, 1570, 1500, 1450, 1380, 1310, 1290,1260, 1210, 1180, 1120, 1070, 1040,1000, 960, 910, 860, 760, 720, 690cm⁻¹.

Anal. calcd. for C₁₆H₈N₃O₂Cl₃ (380.60 g/mol): C, 50.48; H, 2.11; and N,11.04. Found: C, 50.53; H, 2.36; and N, 10.86%.

Example 4 Chiral stationary phase FSC 5

A mixture of silica gel LiChrospher 100 NH₂ (2.00 g,1.4 mmol of N₂),chiral prepared in the Example 3, (0.628 g, 1.59 mmol) and EEDQ (0.39 g,1.59 mmol) is stirred in dichloromethane (10 ml) at room temperature for16 hr. After addition of methanol (50 ml) stirring is continued for 30min. The stationary phase is then separated by filtration, is washedwith methanol, then dried at 70° C. for 4 hr. 2.15 g of the stationaryphase FSC 5 are obtained.

Anal. found: C 8.08%, H 1.05%, N 1.66%. The % of N reveals that 1.0 g ofthe stationary phase contains 0.39 mmol of chiral selector.

Example 54-{n-butyl-[R-1-(cyclohexyl)ethyl-N-R-(naphth-1-yl)methyl]acetamido}amino-2,5,6-trichloro-1,3-dicyanobenzene

R-1-(Cyclohexyl)ethylamine (CEA) (1.59 g, 12.5 mmol) and1-chloromethylnaphthalene (2.45 g, 12.5 mmol) are dissolved in methanol(5 ml). Triethylamine (5 ml) is added. Reaction solution is heated for 3hr under reflux, then evaporated to dryness. The solid residue isdissolved in dichloromethane (50 ml). The organic solution is washedwith 1M aq. sodium bicarbonate, then with water. It is filtered throughcotton-plug and evaporated. It afforded the oilyN-(naphth-1-yl)-R-1-(cyclohexyl)ethylamine (2.23 g. 65%). The amine(2.13 g, 8 mmol) is then dissolved in dichloromethane (25 ml) andtriethylamine (0.81 g, 8.0 mmol) added. To this solution isochloroacetylchloride (0.90 g, 9.0 mmol) in dichloromethane (25 ml) is addeddropwise. After 1 hr stirring at ambient temperature reaction solutionis washed with 1M aq. bicarbonate. The organic phase is filtered througha cotton-plug and evaporated leaving 2.70 g (98%) ofN-chloroacetyl-N-(naphth-1-yl)methyl-R-cyclohexylamine. This product isdissolved in methanol (10 ml), then n-butanol (5 ml) is added, and thereaction solution is heated under reflux for 5 hr. On evaporation todryness, the residual oil is dissolved in dichloromethane (50 ml), thenit is washed with 1M bicarbonate and water, filtered and evaporated,affording an oily product (3.01 g, 99%). Said amine (2.79 g, 7.33 mmol)and 2,4,5,6-tetrachloro-1,3-dicyanobenzene (0.97 g, 3.65 mmol) areheated in acetonitrile (20 ml) under reflux for 2 hr. On evaporation todryness, the residue is dissolved in toluene and purified bychromatography on silica gel (40 g), using first toluene thentoluene/acetone (30:1) as eluent. On evaporation of the fractionscontaining the pure product, 1.70 g (76%) of the pure title compound areobtained.

IR (KBr): 3030, 2920, 2850, 2220, 1650, 1600, 1550, 1510, 1450, 1410,1375, 1310, 1220, 1200, 1175, 1125, 1065, 980, 910, 800, 770, 730, 695,650, 620 cm⁻¹.

Anal. calcd. for C₃₃H₃₅N₄OCl₃ (609.99 g/mol): C, 64.97; H, 5.78; and N,9.18. Found: C, 65.01; H, 5.89; and N, 9.15%.

Example 64-{n-butyl-[R-1-(cyclohexyl)ethyl-N-R-(naphth-1-yl)methyl]acetamido}amino-6-(3-triethoxysilyspropyl)amino-2,5-trichloro-1,3-dicyanobenzeneand4-{n-butyl-[R-1-(cyclohexyl)ethyl-N-R-(naphth-1-yl)methyl]acetamido}amino-2-(3-triethoxysilylpropyl)amino-5,6-trichloro-1,3-dicyanobenzene

The chiral selector (1.00 g, 1.63 mmol) prepared in the Example 5 and3-aminopropyltriethoxysilane (APTES) (3.0 ml) are heated at 100° C. for1 hr. The crude product is purified by chromatography on silica gelcolumn (30 g) using first toluene then toluene/acetone (30:1) as eluent.On evaporation of fractions containing the product, 0.99 g (76%) of pureproduct are obtained, as a mixture of title isomers (3:1).

IR (KBr): 3400, 3340, 2960, 2920, 2720, 2200, 1650, 1570, 1510, 1460,1440, 1410, 1390, 1360, 1340, 1300, 1260, 1220, 1200, 1160, 1100, 950,890, 840, 790, 770, 680 cm⁻¹.

Anal. calcd. for C₄₂H₅₇N₅SiO₄Cl₂ (794.89 g/mol): C, 63.45; H, 7.22; andN, 8.81. Found: C, 63.49; H, 7.48; and N, 8.88%.

Example 7 Chiral Stationary Phase FSC 8

A mixture of isomers (0.90 g, 1.15 mmol) as prepared in the Example 6and Nucleosil 100-5 (2.03 g) are heated under reflux in dry toluene (5ml) for 20 hr. The silica gel is filtered off, is washed with coldtoluene, and dried in vacuo at 70° C. for 4 hr. It is obtained 2.26 g ofthe chiral stationary phase FSC 8.

Anal found: C, 8.73%; H, 1.62%; and N, 1.46%. According on % of N it iscalculated that 0.21 mmol of chiral selector is bound at 1 g of chiralstationary phase.

Example 84-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]ethyl}amino-2,5,6-trichloro-1,3-dicyanobenzene

2,4,5,6-Tetrachloro-1,3-dicyanobenzene (5.0 g, 18.8 mmol) and1,2-diaminoethane (5.0 ml) are stirred in methanol (100 ml) for 1 h atambient temperature. The precipitate is collected on filter and iswashed with methanol, then acetone, affording 4.41 g (81%) of pureproduct as pale-yellowpowder:4-(2-aminoethylamino)-2,5,6-trichloro-1,3-dicyanobenzene. Thisproduct is characterised as follows: Anal calcd. for C₁₀H₇N₄Cl₃ (289.54g/mol): C, 41.47; H, 2.43; and N, 19.35. Found: C, 41.62; H, 2.46; andN, 19.23%.

2-(6-Methoxy-naphth-2-yl)-propionic acid (0.50 g, 2.17 mmol) isdissolved in THF (5.0 ml). To the solution DCC (0.45 g, 2.17 mmol) inTHF (5.0 ml) is added and then the compound above prepared (0.63 g, 2.2mmol) in dry THF (10 ml) is added. After 2 h stirring at ambienttemperature reaction mixture is filtered through a cotton plug. Thefiltrate diluted with 2-propanol (50 ml) and evaporated to final volumeof ca 10 ml. On cooling pure product is precipitated, on after washingwith 2-propanol and drying 0.85 g (78%) of pure product are obtained.

IR (KBr): 3380, 3220, 3180, 3040, 2950, 2220, 1650, 1610, 1570, 1510,1450, 1390, 1340, 1300, 1260, 1210, 1160, 1120, 1020, 950, 920, 890,850, 810, 750 i 700 cm⁻¹.

Anal calcd. for C₂₄H₁₉N₄O₂Cl₃ (501.77 g/mol): C, 57.44; H, 3.81; and N,11.16. Found: C, 57.38; H, 3.62; and N, 11.15%.

Example 94-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]ethyl}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzeneand4-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]ethyl}amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene

The compound prepared in Example 8 (0.7 g, 1.39 mmol) and3-aminopropyltriethoxysilane (3.0 ml) are heated at 100° C. bathtemperature for 60 min. Purification by chromatography on silica gelcolumn (35 g) with toluene as eluent afforded 0.92 g (96%) of the pureisomeric 1:1 product mixture.

IR (KBr): 3340, 2950, 2200, 1650, 1570, 1510, 1450, 1390, 1350, 1260,1200, 1150, 1060, 960, 850 i 760 cm⁻¹.

Anal. calcd. for C₃₃H₄₁O₅N₅Cl₂Si (686.68 gmol⁻¹): C, 57.71; H, 6.01; andN, 10.20. Found: C, 57.63; H, 5.98; and N, 10.28%.

Example 10 Chiral Stationary Phase FSC 10

A mixture of isomers (0.700 g; 1.01 mmol) as prepared in the Example 9and Nucleosil 100-5 (1.69 g) are heated under reflux in dry toluene (5ml) for 20 h. The modified silica gel is filtered off, washed with coldtoluene, and dried in vacuo at 70° C. for 4 hr. 2 g of the chiralstationary phase FSC 10 are obtained.

Anal. found: C, 8.67%; H, 1.77% and N, 1.26%. According to the elementalanalysis it is calculated that 0.18 mmol of chiral selector is bound at1 g of chiral stationary phase.

Example 11 4-N-L-Asparagyl-2,5,6-trichloro-1,3-dicyanobenzene

To the suspension of 2,4,5,6-tetrachloro-1,3-dicyanobenzene (5.0 9; 18.8mmol) in methanol (100 ml) a preheated solution of L-asparaginemonohydrate (5.64 g; 37.6 mmol) and sodium carbonate (3.98 g; 37.60mmol) in water (100 ml) are added. The reaction mixture is heated atreflux for 1.5 h and filtered. The filtrate is washed withdichloromethane (2×100 ml), the aq. layer acidified with 1 M HCl (50 ml)and the acidic solution extracted with dichloromethane (2×100 ml). Theorganic phase is washed with water, filtered, concentrated to 100 ml.After storage in the refrigerator for 2 hr the solid product isprecipitated and collected on G-4 filter. 2.51 g (37%) of title productas white solid material are obtained.

IR (KBr): 3480, 3360, 3320, 2900, 2500, 2220, 1730, 1650, 1570, 1500,1400, 1320, 1200, 1120, 850, 810 cm⁻¹.

Anal. calcd. for C₁₂H₇N₄O₃Cl₃ (361.56): C, 39.86; H, 1.9; and N, 15.49.Found: C, 39.92; H, 2.12; and N, 15.41%.

Example 12 Chiral Stationary Phase FSC 13

The suspension of example 11 (0.55 g, 1.52 mmol), silica gel LiChrospher100 NH₂ (1.96 g; 1.40 mmol of N2), and EEDQ (0.37 g; 1.52 mmol) in dryTHF (10 ml) are stirred at room temperature for 16 h. The product iscollected on G-4 filter, washed with methanol and dried at 70° C. for 4hr to afford 2.18 g of FSC 13.

Anal. found C, 8.95%; H 1.43%; N 1.78%. According to %N it is calculatedthat 1.0 g of chiral stationary phase contains 0.14 mmol of chiralselector.

Example 134-[L-prolinyl-L-alanilyl-(3,5-dimethylanilide)]-2,5,6-trichloro-1,3-dicyanobenzene

N-Boc-L-alanine (2.77 g; 14.6 mmol) is transformed in3,5-dimethylanilide by DCC (3.02 g, 14.6 mmol) promoted condensationwith 3,5-dimethylaniline (1.77 g, 14.6 mmol), using dichloromethane asthe solvent at ambient temperature. 1.78 g (63%) of the crude productare obtained. To 4-N-L-prolinyl-2,5,6-trichloro-1,3-dicyanobenzene (2.55g; 7.4 mmol) dissolved in dichloromethane (15.0 ml) DCC (1.53 g, 7.4mmol) in 10 ml dichloromethane is added, then a solution of3,5-dimethylanilido-L-alanine (1.42 g; 7.4 mmol) in dichloromethane(15.0 ml). After 18 h stirring at ambient temperature the crude productis isolated on filtration on DC-urea and evaporation, then purified bychromatography on silica gel column using toluene-acetone (100:3) aseluent. It is obtained 1.95 g (50%) of the pure product as pale-yellowpowder.

IR (KBr): 3380, 3300, 2980, 2920, 2880, 2220, 1660, 1610, 1550, 1520,1440, 1350, 1260, 1210, 1170, 1140, 1060, 1000, 970, 920, 890, 840, 750,730, 690 cm⁻¹.

Example 144-[L-prolinyl-L-alanilyl-(3,5-dimethylanilide)]-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-[L-prolinyl-L-alanilyl-(3,5-dimethylanilide)]-2,5-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene

The compound from Example 13 (0.81 g; 1.55 mmol) and3-aminopropyltriethoxysilane (3.0 ml) are reacted and the pure productis isolated by purification on silica gel column (30 g) by elution withtoluene-acetone (20:1). 0.79 g (72%) of the mixture of the title isomers(1:1) are obtained.

IR (KBr): 3360, 2980, 2920, 2880, 2200, 1650, 1610, 1570, 1520, 1450,1390, 1350, 1300, 1260, 1220, 1160, 1080,950, 840, 780 i 690 cm⁻¹.

Example 15 Chiral Stationary Phase FSC 18

A mixture of isomers from Example 14 (0.70 g, 1.0 mmol) and silica gelLiChrospher Si 100 (2.0 g, 10 mm) are heated under reflux of dry toluenefor 20 h. The modified silica is collected on G-4 filter, is washed withtoluene, then with 2-propanol, and n-hexane. On drying at 70° C. for 4 h1.94 g of FSC 18 are obtained.

Elem. anal. found: C, 5.78%; H, 1.14%; and N, 1.92%; indicates that 1.0g of CSP contains 0.109 mmol of the bound selector.

Example 16 Stationary Phase FS

A mixture of Nucleosil 100-5 NH₂ (2.0 g, 3.49%C, 1.18% N, 1.94 mmol) and2,4,5,6-tetrachloro-1,3-dicyanobenzene (1.0 g, 3.9 mmol) are heated indry DMF (15.0 ml) at 100° C. for 20 h. The product is collected onfilter, washed with DMF, then with dichloromethane and with MeOH. Ondrying at 70° C. for 4 h 1.2 g of stationary phase are obtained whichhas: Elem. anal. found : C, 5.57%; H, 1.07%; and N, 1.18%; indicatesthat 1.0 g of CSP contains 0.216 mmol of the bound material (based onC).

2.17 g of said stationary phase is heated in 1,2-diaminoethane (10.0 ml)for 16 h at 90° C. bath temperature. Product is collected on G4 filter,is washed with 1 m sodium carbonate, then methanol. On drying for 4 h at70° C. is obtained 2.12 g of stationary phase FS.

Elem. anal. found: C, 6.19%; H, 1.33%; and N 1.24%; indicates that 1.0 gof CSP contains 0.021 mmol of the bound 1,2-diaminomethane (based on C).

Example 17 Chiral Stationary Phase FSC 19

To the suspension of FS of example 16 (2.0 g) in dry THF (20.0 ml) areadded N-3,5-dinitrobenzoyl-L-leucine (1.9 g, 5.8 mmol) and EEDQ (1.44 g,5.8 mmol). The reaction mixture is stirred for 16 h at ambienttemperature, then FSC 19 is isolated as previously described, affording2.24 g of the product.

Elem. anal. found : C, 12.98%; H, 1.41%; and N, 1.71%; indicates that1.0 g of CSP contains 0.434 mmol of the bound DNB-Leu (based on C).

Example 18 Chiral Stationary Phase FSC 20

To the suspension of FS (2.0 g) in dry THF (20.0 ml) are addedN-3,5-dinitrobenzoyl-L-phenylglycine (2.0 g, 5.82 mmol) and EEDQ (1.44g, 5.8 mmol). The reaction mixture is stirred for 16 h at ambienttemperature, then FSC 20 isolated as previously described, affording2.23 g of the product.

Elem. anal. found: C, 12.58%; H, 1.77%; and N 2.09%; indicates that 1.0g of CSP contains 0.354 mmol of the bound DNB-Phegly (based on C).

Example 194-[(2-amino)cyclohexylamino]-2,5,6-trichloro-1,3-dicyanobenzene

To the slurry of 2,4,5,6-tetrachloro-1,3-dicyanobenzene (2.0 g, 7.5mmol) in acetonitrile (40 ml) triethylamine (5.0 ml) is added, then1,2-diaminocyclohexane (0.86 g, 7.5 mmol) and the reaction mixture isheated under reflux for 1 h. It is cooled to ambient temperature, thendeposited on ice for few hours, and the crystalline product is collectedon filter. 2.32 g (89%) of the title product as pale-yellow powder areobtained.

IR (KBr): 3340, 3300, 3120, 2960, 2920, 2860, 2220, 1600, 1580, 1480,1450, 1400, 1360, 1350, 1270, 1240, 1220, 1190, 1100, 1070, 1040, 990,930, 900, 870, 850, 840, 740, 730 i 610 cm⁻¹.

Anal. calcd. for: C₁₄H₁₃N₄Cl₃ (343.63 g/mol): C, 48.93; H, 3.81; and N,16.30. Found: C, 48.77; H, 4.01; and N, 16.35%.

Example 204-[2-(3,5-dinitrobenzoyl)amide-cyclohexyl]amino-2,5,6-trichloro-1,3-dicyanobenzene

To the solution of the compound obtained in Example 19 in THF (40 ml)triethylamine (1.0 ml) is added, then solution of3,5-dinitrobenzoylchloride (0.68 g, 295 mmol) in THF (10 ml). After 1 hstirring at ambient temperature the solvent is evaporated in vacuo andthe solid residue is slurried in methanol (50 ml). After 10 minsonification in an ultrasound bath the product is collected on filter,is washed with methanol and dried to afford 1.18 g (75%) of whitepowder.

IR (KBr): 3300, 3260, 3100, 2920, 2860, 2220, 1640, 1570, 1540, 1510,1340, 1200, 1100, 1080, 920, 870, 850, 770, 750 i 720 cm⁻¹.

Anal. calcd. for: C₂₁H₁₅N₆O₅Cl₃ (537.73 g/mol): C, 46.90; H, 2.81; andN, 15.63. Found: C, 46.97; H, 3.01; and N, 15.52%.

Example 214-{[2-(3,5-dinitrobenzoyl)-cyclohexyl]amide}-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and 4-{[2-(3,5-dinitrobenzoyl)-cyclohexyl]amide)amino-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene

The compound from example 20 (1.0 g, 1.85. mmol) is dissolved in3-aminopropyltriethoxysilane (5.0 ml) and DMF (1.0 ml) is added. Thenthe resulting solution is heated for 1 h at 100° C. bath temperature.After evaporation in vacuo, the crude product is purified on silica gelcolumn (30 g), by elution with toluene. It is obtained a re 1:1 mixtureof the title isomers (1.27 g, 94%).

IR (KBr): 3420, 3100, 2980, 2920, 2880, 2210, 2200, 1600, 1590, 1500,1500, 1450, 1390, 1340, 1220, 1190, 1160, 1100, 1080, 950, 780, 730,720, 680 cm⁻¹.

Anal. calcd. for C₃₀H₃₈N₇O₈Cl₂Si (723.64): C, 49.78; H, 5.29; and N,13.55. Found: C, 50.03; H, 5.75; and N, 13.28%.

Example 22 al Stationary Phase FSC 22

A mixture of isomers from example 21 (1.0 g, 1.35 mmol) and Nucleosil100-5 (1.63 g) are heated for 20 h under reflux in dry toluene (15 ml).The product is collected on G-4 filter, washed first with toluene thenwith 2-propanol, and n-hexane. On drying at 70° C. for 4 h, 1.95 g ofchiral stationary phase FSC 22 are obtained.

Elem. anal. found: C, 7.98%; H, 1.34%; and N, 1.26%; indicates that 1.0g of FSC contains 0.128 mmol of the bound selector (based on C).

Example 23 Chiral Stationary Phase FSC 24

A suspension of FS prepared above (2.0 g),N-3,5-dinitrobenzoyl-L-phenylalanine (2.1 g; 5.8 mmol) and EEDQ (1.44 g;5.8 mmol) in dry THF (20 ml) are stirred for 16 h at ambienttemperature. The modified silica gel is collected on G-4 filter, washedwith methanol and dried at 70° C. for 4 h to afford 2 g of FSC 24.

Example 24 Chiral Stationary Phase FSC 25

Silicagel LiChrospher 100 NH₂ (2.0 g) is slurried in THF (10 ml), then2,4,5,6-tetrachloro-1,3-dicyanobenzene (0.67 g, 2.5 mmol) and EEDQ (0.60g, 2.5 mmol) are added. The reaction mixture is stirred for 16 h atambient temperature. ThenN-3,5-dinitrobenzoylamido-D-phenylglycine(2-aminoethyl-(aminoethyl)-amide)(8.0 mmol) is added and stirring at 65° C. is continued for 6 h. Theresulting stationary phase FSC 25 is collected on filter, washed withmethanol, and dried at 70° C. for 4h. It is obtained ca 3 g of FSC 25.

Example 25 Chiral Stationary Phase FSC 26

Starting from silicagel Lichrospher 100 NH₂ (3.0 g) and2,4,5,6-tetrachloro-1,3-dicyanobenzene (1.12 g, 4.2 mmol), and EEDQ(1.61 g, 6.5 mmol). The reaction mixture is stirred for 16 h at ambienttemperature. ThenN-3,5-dinitrobenzoylamido-D-phenylglycine-(meta-aminomethylphenyl)-methylamide(15.0 mmol) is added and stirring at 60° C. continued for 12 h. Theresulting stationary phase is collected on filter, is washed withmethanol, and dried at 70° C. for 4 h. It is obtained 4.4 g of thestationary phase FSC 26.

Example 26 Chiral Stationary Phase FSC 27

Silicagel Lichrospher 100 NH₂ (3.0 g) and2,4,5,6-tetrachloro-1,3-dicyanobenzene (1.06 g, 4.0 mmol), are slurriedin tetrahydrofurane (20 ml), and EEDQ (1.48 g, 6.0 mmol) is added. Thereaction mixture is stirred for 16 h at ambient temperature. ThenN-3,5-dinitrobenzoylamido-D-phenylglycine-(para-aminomethylphenyl)methyl-amide(12.0 mmol) is added and stirring at 60° C. continued for 8 h. Theresulting stationary phase is collected on filter, is washed withmethanol, and dried at 70° C. for 4 h. 4.2 g of the stationary phase FS27 are obtained.

Example 27 Chiral Stationary Phase FSC 28

Starting from silica gel Lichrospher 100 NH₂ (6.0 g) and2,4,5,6-tetrachloro-1,3-dicyanobenzene (2.66 g, 10 mmol), and EEDQ (3.71g, 15 mmol). The reaction mixture is stirred for 16 h at ambienttemperature ThenN-3,5dinitrobenzoylamido-D-phenylglycine-(2-aminocyclohexyl)amide (35mmol) is added and stirring at 60° C. continued for 10 h. The resultingstationary phase is collected on filter, is washed with methanol, anddried at 70° C. for 4 h. 7.1 g of the FSC 28. are obtained.

Chemical analysis of chiral selectors and chiral stationary phasesprepared according to the present invention Example 28 Chiral StationaryPhase FSC 2

Analysis, found; C, 8.32; H, 1.21; N, 1.69%. According to elementalanalysis 0.17 mmol of the chiral selector is bound on 1.0 g of silicagel.

Example 294-[(3,5-Dimethylanilido)-L-phenylalaninyl]-6-(3-triethoxysilyl)propylamino-2,5-dicloro-1,3-dicyanobenzene,and4-[(3,5-dimethylanilido)-L-phenylalaninyl]-2-(3-triethoxysilyl)propylamino-5,6-dicloro,1,3-dicyanobenzene

IR (KBr): 3320, 3020, 2980, 2920, 2880, 2200, 1690, 1670, 1610,1570,1500, 1460, 1440, 1390,1360, 1340,1320, 1215, 1160, 1100,950, 840,790,770,740, 700,680 cm⁻¹.

Anal. calcd. for C₃₄H₄₁N₅O₄Cl₂Si (682.69 g/mol): C, 59.81; H, 6.05 andN, 10.26. Found: C, 59.75; H, 6.15; and N, 10.29%.

Example 304-[(Naphth-1-yl)amido)-L-phenylalaninyl]-2-(3-triethoxypropyl)amino-5,6-dichloro-1,3-dicyanobenzene and 4-[(Naphth-1-yl)amido)-L-phenylalaninyl]-6-(3-triethoxypropyl)amino-2,5-dichloro-1,3-dicyanobenzene

IR (KBr): 3400, 3350, 3060, 3020, 2980, 2920, 2880, 2720, 2200, 2220,1690, 1670, 1590, 1510, 1450, 1400, 1370, 1350, 1300, 1270, 1250, 1200,1160, 1100, 1080, 950, 800, 770, 750, 700 cm⁻¹.

Analysis calcd. for: C₃₆H₃₉N₅O₄Cl₂Si (704.70 g/mol): C, 61.35; H, 5.57and N, 9.94. Found: C, 61.12; H, 5.75; and N, 9.98%.

Example 31 Chiral Stationary Phase FSC 3

Anal. found: C, 8.99%; H, 0.98%; N, 1.58%. The % N reveals that 1.0 g ofthe stationary phase contains 0.23 mmol of chiral selector.

Example 32 Chiral Stationary Phase FSC 4

Anal. found: C, 8.02%; H, 1.03%; N, 1.65%. The % N reveals that 1.0 g ofthe stationary phase contains 0.23 mmol of chiral selector.

Example 334-[R-1-(naphth-1-yl)ethyl]amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzeneand4-[R-1-(naphth-1-yl)ethyl]amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzene

IR (KBr): 3390, 3370, 2980, 2920, 2880, 2200, 1580, 1510, 1500, 1440,1390, 1360, 1300, 1270, 1220, 1190,1160, 1100,1070, 950, 760, 700 cm⁻¹.

Anal. calcd. for C₂₉H₃₄N₄SiO₃Cl₂ (585.57 g/mol): C, 59.47; H, 5.85 ; andN, 9.57%. Found: C, 59.41; H, 5.98; and N, 9.55%.

Example 34 Chiral Stationary Phase FSC, 6

Anal. found: C, 6.51%; H, 1.33%; N, 1.23%. According to % of N it iscalculated that 1.0 g of the stationary phase contains 0.22 mmol ofchiral selector.

Example 354-{n-butyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzene,and4-{n-butyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene

IR (KBr): 3390, 3100, 2980, 2920, 2880, 2220, 1670, 1575, 1520, 1460,1420, 1390, 1360, 1340, 1310, 1290, 1240, 1210, 1190, 1160, 1100, 1080,950, 800, 780 cm¹.

Anal. calcd. for C₃₅H₄₅N₅SiO₄Cl₂ (698.73 g/mol): C, 60.15; H, 6.49; andN, 10.02. Found: C, 60.27; H, 6.57; and N, 9.81%.

Example 36 Chiral Stationary Phase FSC 7

Analysis, found; C, 7.16%; H, 1.16%; N, 1.78%. According to elementalanalysis. 0.25 mmol of the chiral selector is bound on 1.0 g of silicagel.

Example 374-{n-butyl-[N-R-1-(cyclohexyl)ethyl-N-3,5-dinitrobenzyl]acetamido}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzeneand4-{n-butyl-[N-R-1-(cyclohexyl)ethyl-N-3,5-dinitrobenzyl]acetamido}amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene

Anal. calcd. for C₃₈H₅₃N₇SiO₈Cl₂ (834.85 g/mol): C, 54.66; H, 6.39; andN, 11.74. Found: C, 54.73; H, 6.28; and N, 11.69.

Example 38 Chiral Stationary Phase FSC 9

Anal. found: C, 6.69%; H, 1.56%; and N, 1.78%. According on % ofnitrogen: 0.18 mmol of chiral selector is bound at 1g of chiralstationary phase.

Example 394-{methyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene, and4-{methyl-[R-1-(naphth-1-yl)ethyl]acetamido}amino-6-(3-Triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzene

IR (KBr): 3380, 2980, 2920, 2880, 2200, 1670, 1580, 1510, 1450, 1390,1360, 1300, 1220, 1160, 1100, 950, 780 cm⁻¹.

Anal. calcd. for C₃₂H₃₉N₅SiO₄Cl₂ (656.66): C, 58.52; H, 5.98; and N,10.66. Found: C, 58.48; H, 6.12; and N, 10.77%.

Example 40 Chiral Stationary Phase FSC 11

Anal. found C, 6.60%; H, 0.95%; and N, 1.27%. On the basis of nitrogen:1.0 g of chiral stationary phase contain 0.18 mmol of chiral selector.

Example 41 Chiral Stationary Phase FSC 12

Anal. found. C, 8.83%; H, 1.38%; and N, 1.71%. On the basis of % N it iscalculated that 1.0 g of chiral stationary phase contain 0.17 mmol ofchiral selector.

Example 42 4-[3,5-dimethylanilido)-L-alaninyl]-Z5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene, and4-[3,5-dimethylanilido)-L-alaninyl]-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene

IR (KBr): 3325, 2980, 2920, 2880, 2200, 1680, 1610, 1590, 1510, 1450,1390, 1200, 1160, 1100, 1080, 950, 840, 780, 690 cm⁻¹.

Anal. calcd. for C₂₈H₃₇N₅O₄Cl₂Si (606.61): C, 55.43; H, 6.14; and N,11.54. Found: C, 55.25; H, 6.16; and N, 11.82%.

Example 43 Chiral Stationary Phase FSC 14

Anal. found C, 6.42%; H, 1.14%; N, 1.52%. On the basis of % N it iscalculated that 1.0 g of stationary phase contains 0.22 mmol of chiralselector.

Example 444-(cyclohexylamido-L-alaninyl)-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-(cyclohexylamido-L-alaninyl)-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene

IR (KBr): 3330, 2980, 2920, 2210, 1660, 1580, 1500, 1450, 1390, 1360,1350, 1310,1290, 1250, 1220, 1200, 1160,1100,1070, 950, 890, 770 cm⁻¹.

Anal. calcd. for C₂₆H₃₉N₅O₄Cl₂Si (584.60): C, 53.41; H, 6.72; and N,11.98. Found: C, 53.18; H, 6.59; and N, 11.79%.

Example 45 Chiral Stationary Phase FSC 15

Anal. found C, 7.00%; H, 1.37%; and N, 1.49%. On the basis of % N it iscalculated that 1.0 g of chiral stationary phase contains 0.21 mmol ofchiral selector.

Example 564-[(3,5-dimethylanilido)-prolinyl]-Z5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-[(3,5-dimethylanilido)-prolinyl]5,6-Dichloro-2-(3-triethoxysilylpropyl)amino1,3-dicyanobenzene

IR (KBr): 3330, 2990, 2960, 2940, 2200, 1680, 1610, 1580, 1530, 1450,1390, 1350, 1300, 1200, 1160, 1000, 950, 840,780, 690 cm⁻¹.

Elem. anal. calcd. for C₃₀H₃₉N₅O₄Cl₂Si (632.64): C, 56.95; H, 6.21; andN, 11.07. Found: C, 57.12; H, 5.96; and N, 11.02%.

Example 47 Chiral Stationary Phase FSC 16

Anal. found : C, 8.01%; H, 1.91%; and N, 1.72%; indicates that 1.0 g ofCSP contains 0.25 mmol of the bound selector.

Example 484-(prolinyl-cyclohexylamide)-2,5-dichloro-6-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene,and4-(prolinyl-cyclohexylamide)-5,6-dichloro-2-(3-triethoxysilylpropyl)amino-1,3-dicyanobenzene

IR (KBr): 3440, 2990, 2960, 2940, 2200, 1660, 1580, 1520, 1470, 1450,1390, 1350, 1300, 1200, 1190, 1160, 1100, 1080, 950, 780 cm⁻¹.

Anal. calcd. for C₂₈H₄₁N₅O₄Cl₂Si (610.64): C, 55.06; H, 6.76; and N,11.47. Found: C, 55.18; H, 6.38; and N, 11.30%.

Example 49 Chiral Stationary Phase FSC 17

Elem. anal. found : C, 7.42%, H, 1.67% and N, 1.63%, indicates that 1.0g of CSP contains 0.23 mmol of the bound selector.

Example 504-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]cyclohexyl}amino-6-(3-triethoxysilylpropyl)amino-2,5-dichloro-1,3-dicyanobenzeneand4-{2-[2-(6-methoxy-naphth-2-yl)-propionylamido]cyclohexyl}amino-2-(3-triethoxysilylpropyl)amino-5,6-dichloro-1,3-dicyanobenzene

IR (KBr): 3350, 2940, 2200, 1650, 1580, 1510, 1450, 1390, 1350, 1260,1200, 1160, 1070, 950, 850 i 770 cm⁻¹.

Anal. calcd. for C₃₇H₄₈N₅O₅Cl₂Si (741.78 g/mol): C, 59.90; H, 6.52; andN, 9.44. Found: C, 60.04; H, 6.48; and N, 9.37%.

Example 51 Chiral Stationary Phase FSC 23

Elem. anal. found: C, 7.98%; H, 1.34%; and N, 1.26%; indicates that 1.0g of CSP contains 0.172 mmol of the bound chiral selector (based on N).

Examples of Resolution of Racemates with Chiral Stationary PhasesAccording to the Present Invention Example 52 Resolution of Racematewith FSC

Chromatographic column for HPLC is filled with FSC and several racemicmixtures were separated using n-hexane/2-propanol (9:1) as eluent. Twoenantiomers for each of mixture tested were resolved as completelyseparated symmetric peaks with Rt₁ and Rt₂ given in table 1 (Rt₁ and Rt₂mean the retention time for each peak, in minutes):

TABLE 1 Rt₁ Rt₂ FSC 10 TR19 9.53 13.52 FSC 8 TR22 5.50 8.00 FSC 7 TR1711.1 20.1

Example 53 Chromatographic Separation of Racemates with FSC

A number of racemic mixtures are employed as analytes to evaluate thechromatographic performance of several FSC. The eluent used is eithern-hexane/2-propanol (9:1) (A) or n-hexane/dichloromethane/methanol(100:30:1) (B). The results are reported in Table 2.

TABLE 2 Separation of several racemic analytes listed in FIG. 6 with thestationary phases of the invention. The letter in brackets refers to theeluent used. racemic analyte FSC 10 (A) FSC 8 (A) FSC 18 (A) FSC 13 (A)TR17 k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) 6.10 8.592.62 3.96  5.17 2.45 2.64 8.75 13.41  3.81  3.93  0.21 FSC 11 (A) FSC 7(A) FSC 10 (A) FSC 18 (A) TR19 k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S)k′₁ k′₂ R_(S) 5.19 10.89 7.29 3.91  7.74 5.28 3.96 6.04  3.98  1.29 6.60 17.97 FSC 3 (B) FSC 7 (A) FSC 8 (A) FSC 18 (A) TR23 k′₁ k′₂ R_(S)k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) 2.61 3.57 3.37 8.43 17.8 6.315.09 7.26  6.25  3.06 10.26  3.77 FSC 1 (A) FSC 5 (A) FSC 13 (A) FSC 20(A) TR6 k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) 2.082.18 0.50 2.99  3.25 0.72 1.31 1.41  0.69  1.51  1.79  0.58 FSC 1 (B)FSC 13 (B) FSC 12 (B) FSC 20 (A) TR8 k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂R_(S) k′₁ k′₂ R_(S) 2.03 2.16 0.84 4.84  5.08 0.78 3.54 3.82  1.02 11.4614.53  0.72 FSC 11 (B) FSC 12 (A) FSC 4 (A) FSC 19 (A) TR9 k′₁ k′₂ R_(S)k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) 2.52 2.65 0.55 1.62  1.76 0.581.06 1.22  0.34  2.89  3.53  0.37 FSC 11 (A) FSC 7 (A) FSC 3 (A) FSC 12(A) TR15 k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) k′₁ k′₂ R_(S) 1.401.56 0.84 0.26  0.28 0.89 0.25 0.44  1.31  2.77  2.95  0.82

What is claimed is:
 1. A chiral selector of formula (I) wherein:X=NR₁—CHR₂R₃ R₁ is selected from: H, branched or linear alkyl having 1to 6 carbon atoms, R₂ is selected from: the group consisting of H,branched or linear alkyl having 1 to 6 carbon atoms, aryl or arylalkyl,containing or not containing a heteroatom, being said aryl or arylalkylsubstituted or unsubstituted with —OH or —CH₂CONH₂, R₃ is selected from:branched or linear alkyl having 1 to 6 carbon atoms, (CH₂)_(p)—COOH,(CH₂)_(p)—CONH₂, (CH₂)_(p)—CONHR₄, (CH₂)_(p)—NHCOR₄,(CH₂)_(p)—CON(R₄R₅), CONHCH(R₄)CONHR₄, (CH₂)_(p)—NHCOCH(R₄)NHCOR₄,C₆H₄—CH₂—NHCOCH(R₄)NHCOR₄ and CH₂NH(CH₂)_(p)—NHCOCH(R₄)NHCOR₄, where pis an integer from 0 to 4, R₄ and R₅ are independently selected from thegroup consisting of: (a) linear or cyclic alkyl having from 1 to 6carbon atoms, (b) aryl, and (c) a spacer group of formula—(CH₂)_(n)—Si—(OR₆)₃ where n ranges from 1 and 10 and R₆ is an alkylwith 1 to 4 carbon atoms; said groups (a) and (b) being substituted orunsubstituted with alkyl with 1 to 4 carbon atoms, aryl, cycloalkylhaving 5-6 carbon atoms, NO₂ and OCH₃, or: (i) R₁ forms together withR₂, with the carbon atom bound to R₂ and with the nitrogen, a 5-6membered ring, or (ii) R₂ forms with R₃ and with the carbon atom boundto R₂ and R₃ a 5-6 membered ring substituted by —NHCOR₄, or by—NHCOCH(R₄)NHCOR₄, where R₄ is selected from the group consisting of:(a) linear or cyclic alkyl having from 1 to 6 carbon atoms, (b) aryl,and (c) a spacer group of formula —(CH₂)_(n)—Si—(OR)₃ where n rangesfrom 1 and 10 and R₆ is an alkyl with 1 to 4 carbon atoms, said groups(a) and (b) being unsubstituted or substituted from the group consistingof 1 to 4 carbon atom alkyl, aryl, cycloalkyl having 5-6 carbon atoms,NO₂ and OCH₃, Y and Z independently of each other are selected from thegroup consisting of chloro, X group where X is defined above, a spacergroup of formula —A(CH₂)_(n)—Si—(OR₆)₃ where A represents NH or O, and nand R₆ are defined above; with the proviso that said formula (I)contains: (a) one to three X groups containing at least one chiral atom,and (b) only one spacer group as above defined.
 2. The chiral selectoraccording to claim 1, wherein: R₁ is selected from H, branched or linearalkyl having 1 to 6 carbon atoms; R₂ is selected from H, branched orlinear alkyl having 1 to 6 carbon atoms, aryl, arylalkyl, CH₂CONH₂, orR₁ forms with R₂, with the carbon atom bound to R₂ and with N a 5-6membered ring; and R₃ is selected from a branched or linear alkyl having1 to 6 carbon atoms, (CH₂)_(p)—CONHR₄, (CH₂)_(p)—CON(R₄R₅), where p, R₄and R₅ have the meanings given above.
 3. The chiral selector accordingto claim 1, wherein: R₁ is H, R₂ is H, R₃ is selected from(CH₂)_(p)—NHCOR₄, CH₂—NHCOR₄, where p, R₄ have the meanings given above;or R₂ forms with R₃ and the carbon atom bound to R₂ and R₃ a 5-6membered ring.
 4. The chiral selector according to claim 1, wherein: R₁is H, R₂ is H, or R₂ forms with R₁, with the carbon atom bound to R₂ andwith N a 5-6 membered ring; R₃ is CONHCH(R₄)CONHR₄, where p, R₄ have themeanings given above.
 5. The chiral selector according to claim 1,wherein: R₁ is H, R₂ is H, R₃ is selected from:(CH₂)_(p)—NHCOCH(R₄)NHCOR₄, C₆H₄—CH₂—NHCOCH(R₄)NHCOR₄,CH₂NH(CH₂)_(p)—NHCOCH(R₄)NHCOR₄; or R2 forms with R3 and with the carbonatom bound to R2 and R3 a 5-6 membered ring substituted withNHCOCH(R₄)NHCOR₄; p and R₄ having the meanings given above.
 6. A chiralstationary phase compound of formula (I) wherein: X=NR₁—CHR₂R₃ R₁ isselected from: H, branched or linear alkyl having 1 to 6 carbon atoms,R₂ is selected from: H, branched or linear alkyl having 1 to 6 carbonatoms, aryl or arylalkyl, containing or not containing, a heteroatom,being said aryl or arylalkyl substituted or unsubstituted with —OH, or—CH₂CONH₂, R₃ is selected from: branched or linear alkyl having 1 to 6carbon atoms, (CH₂)_(p)—COOH, (CH₂)_(p)—CONH₂, (CH₂)_(p)—CONHR₄,(CH₂)_(p)—NHCOR₄, (CH₂)_(p)—CON(R₄R₅), CONHCH(R₄) CONHR₄,(CH₂)_(p)—NHCOCH(R₄)NHCOR₄, C₆H₄—CH₂—NHCOCH(R₄)NHCOR₄,CH₂NH(CH₂)_(p)—NHCOCH(R₄)NHCOR₄, where p is an integer from 0 to 4, R₄and R₅ are independently selected from the group consisting of: (a)linear or cyclic alkyl having from 1 to 6 carbon atoms, (b) aryl, and(c) a spacer group of formula —(CH₂)_(n)—Si—(OR₆)₃ where n ranges from 1and 10 and R₆ is an alkyl having 1 to 4 carbon atoms; said groups (a)and (b) being unsubstituted or substituted from the group consisting of1 to 4 carbon atom alkyl, aryl, cycloalkyl having 5-6 carbon atoms, NO₂and OCH₃, or: (i) R₁ forms together with R₂, with the carbon atom boundto R₂ and with the nitrogen, a 5-6 membered ring, or (ii) R₂ forms withR₃ and with the carbon atom bound to R₂ and R₃ a 5-6 membered ringsubstituted by —NHCOR₄, or by —NHCOCH(R₄)NHCOR₄, where R₄ is selectedfrom the group consisting of: (a) a linear or cyclic alkyl having 1 to 6carbon atoms, (b) aryl, (c) a spacer group of formula—(CH₂)_(n)—Si—(OR₆)₃ where n is comprised between 1 and 10 and R₆ is analkyl having 1 to 4 carbon atoms; said groups (a) and (b) beingunsubstituted or substituted with alkyl having 1 to 4 carbon atoms,aryl, cycloalkyl having 5-6 carbon atoms, NO₂ and OCH₃, Y and Zindependently of each other are selected from the group consisting of:chloro, X group where X has the meanings given above, a spacer group offormula —A(CH₂)_(n)—Si—(OR₆)₃ where A represents NH or O, and n and R₆have the meanings given above; with the proviso that said formula (I)contains: (a) one to three X groups containing at least one chiral atom,and (b) only one spacer group as above defined, said compound of formula(I) being bound to a solid organic or inorganic support by means of saidspacer group.
 7. The compound according to claim 6, wherein the solidsupport is selected from the group consisting of silica, silica gel,alumina, kaolin, titanium oxide, magnesium, silicate and syntheticpolymers.
 8. A process for the preparation of chiral stationary phasesof claim 6, further comprising the following separate reaction stepswhich can take place in any order: (a) introducing one or more chiralgroups X on the 1,3-dicyanobenzene ring, said X group having thestructure defined in claim 6, (b) introducing the spacer group either on1,3-dicyanobenzene ring, or on a X chiral group already present on the1,3-dicyanobenzene ring, said spacer group having the structure definedin claim 6, and (c) forming a covalent linkage between the spacer groupand a solid support.
 9. The process according to claim 8, wherein the Xgroups are introduced on the 1,3-dicyanobenzene ring by using reagentscontaining the X group selected from the group consisting of esters ofamino acids, amides of amino acids, arylalkylalchols, arylcarboxylicacids, arylcarboxylic acid esters, arylcarboxylic acid esters,aminoamides and arylalkylamines.
 10. The process according to claim 9,wherein said reagents containing the X group are selected from the groupconsisting of 1-phenylethylamine, proline, (1-(naphth-1-yl)ethylamine,phenylalanine, phenylglycine, n-butylamine, naphthylethylamine,3,5-dimethylaniline, cyclohexylethylamine, sarcosine and asparagine. 11.The process of analytical or preparative chromatographic separation ofenantiomers or mixtures of racemates, comprising the steps of preparingchiral stationary phases according to claim
 6. 12. The process accordingto claim 11, wherein the separation is carried out by high performanceliquid chromatography (HPLC).